Switch mechanism



y 1957 A. D. STOLLE EIAL 2,801,305

swI'rcl-i uscmmxsu Filed Aug. 17, 1954 2 Sheets-Sheet 1 g INVENTORS. BY EM July 30, 1957 A. D. STOLLE EIAL 2,801,305

SWITCH MECHANISM Filed Aug. 17, 1954 2 Sheets-Sheet ZIjNVENTOg.

BYROMBZZZZQ United States Patent SWITCH MECHANISM Anthony D. Stolle and Robert B. Ellis, Chicago, Ill., as-

signors to International Register Company, Chicago, 111., a corporation of Illinois Application August 17, 1954, Serial No. 450,436 12 Claims. Cl. 200-33 Our present invention relates generally to switch mechanisms, and, more particularly, is directed to time switch mechanisms.

It is an object of our present invention to provide a time switch mechanism wherein an electrical circuit between two switch arms may be momentarily interrupted.

Our present invention is concerned with the general type of time switch mechanism comprising a power driven cam having a track with an abrupt radial recess therein and switch arms having associated therewith a cam follower which is engageable with the cam track for urging the switch arms into engagement with each other. When the cam follower is received in the cam track recess, upon completion of a timed cycle, the switch arms are permitted to separate. Time switch mechanisms of the character referred to are disclosed and claimed in the copending application of William P. Gallagher, Anthony D. Stolle, and Robert B. Ellis, Serial No. 393,802, filed November 23, 1953.

It is another object of our present invention to provide a switch mechanism, as noted, wherein the circuit between a pair of the switch arms may be momentarily opened and then closed during, and prior to completion of, a timed cycle of operation of the switch mechanism.

In accomplishing the latter object, we provide switch actuating means which is operable by the cam follower in one range of rotation of the cam to separate one pair of the switch arms. More specifically, a slidable member is associated with the one pair of the switch arms and is adapted to separate the latter. Lever means is pivotally mounted intermediate of its ends to the cam with the one end thereof being adapted to project beyond the periphery of the cam and the other end thereof being adapted to engage the slidable member.

As the cam follower moves into engagement with the said one end of the lever means, upon rotation of the cam, the lever means is pivoted for causing sliding movement of the slidable member whereby the selected switch arms are separated. Upon further rotation of the cam, but prior to completion of a full timed cycle, the said other end of the lever means moves out of engagement with the slidable member for releasing the force applied thereto and permitting the switch arms to re-engage.

It is a feature of our present invention that the selected pair of switch arms, after they have been separated momentarily, are re-engaged without any radial movement being required on the part of the cam follower.

Now, in order to acquaint those skilled in the art with the manner of constructing and using time switches in accordance with the principles of our present invention, we shall describe in connection with the accompanying drawings a preferred embodiment of our present invention.

In the drawings:

Figure 1 is an exploded view of the time switch mechanism of our present invention;

Figure 2 is a front elevational view of the time switch mechanism of Figure 1, with the cover member being broken away; and

Figures 3 through 10 illustrate various sequences of steps in the operation of the time switch mechanism of Figure 1.

Referring now to Figures 1 and ,2, there is indicated generally by the reference numeral 10 the time switch mechanism of our present invention. The time switch mechanism 10 comprises a supporting plate 12 which is preferably formed of insulating material and is gen erally rectangular.

Staked in apertures formed in the upper half of the member 12 are metallic terminal post members 14, 16, 18 and 20, the ends of which project through the member 12 and are adapted to have suitable connection with various electrical devices for timing the operations thereof. The process by which the terminal post members 14, 16, 18 and 20 are staked to the mounting member 12 is disclosed and claimed in the co-pending application of William P. Gallagher, Anthony D. Stolle, and Paul G. Bielik, Serial No. 366,842, filed July 8, 1953.

Secured, as by riveting, to the forward ends of the posts 14, 16 and 20 are the one ends of elongated, metallic switch arms 22, 24 and 26. The other ends of the switch arms 22 and 26 have respectively mounted thereon metallic contacts 28 and 30, the latter of which cooperates with a metallic contact 32 secured to the terminal post 18. The other end of the switch arm 24 has secured thereto an insulating button 34 which is adapted to cooperate with the contact 30 on the switch arm 26. In addition, a metallic contact 35 is secured to the switch arm 24 intermediate of the ends thereof and cooperates with the contact 28.

The contact 28 of the switch arm 22 is further adapted to cooperate with a metallic contact 36 which is carried at the one end of a metallic switch arm 38 having a flanged foot portion 40 which is suitably riveted at 42 to the mounting member 12. The rivets 42 preferably extend through the member 12 and are adapted to support terminal members which may be connected with an electrical device.

A pair of spaced pin members 44 and 46 are secured at their one ends in the member 12 on the opposite sides of the switch arm 24. The upper pin member 44 serves to limit movement of the switch arm 22 in a downward direction, as viewed in Figure 2. A slidable insulating member 48, having a boss or foot portion 49, is formed with a central, elongated opening 50, wider at the lower end than at the upper end. The upper end of the opening 50 is adapted to receive the pin member 44 while the lower end thereof is adapted to receive the pin member 46. When the slidable member 48 is in assembled position, as shown in Figure 2, it lies immediately beneath the switch arms 22 and 24, and its upper end is adapted to engage the switch arm 38. A portion of the switch arm 38 is bent downwardly at 52 and this bent portion engages the slidable member 48 for normally maintaining the latter in the position shown in Figure 2.

So as to effect actuation of the aforedescribed switch arms of the time switch mechanism of our present invention, we provide a non-metallic revolvable member or cam 54 mounted on a shaft 56, which is journaled, at one end in a central aperture 58 formed in the mounting member 12, and at the other end, in a central aperture 60 formed in a cover member 62 having arm members 64. In the assembly of the switch mechanism, lugs 66, which are formed at the ends of the arms 64 of the cover member 62, are inserted through rectangular openings 68 formed at the sides of the mounting member 12 and are then bent or twisted so as to lock the cover 62 in position.

Secured to the shaft 56, intermediate of the cam 54 and the mounting member 12, is a gear 70 which has meshing engagement with a pinion 72 that projects through an aperture 74 formed in the mounting member 12. The pinion 72 is drivingly connected through reduction gearing. with a slow speed synchronous electric motor, the

latter assembly being indicated generally by the reference numeral 76. The electric motor and reduction gearing unit 76 is secured by screws 78 to the mounting member 12, with the electric motor being adapted to be placed in communication with an electric power source through lines 80 and 82; the latter of which are suitably connected to the appropriate switch terminals.

Associated with the switch arm 24 is afloating, metallic C-shaped cam follower 84 which has a body portion 86 and arm portions 88. The switch arm 24, intermediate of the ends thereof, is formed at its opposite edges with spaced flanges 85 that project at right angles therefrom and toward the cam 54. Eachflange 85 is formed in twoparts which define a substantially V-shaped recess 87.

and an abrupt radial recess, having three steps 92, 94 and 96, formed therein. The step 92 is defined by forming the peripheral segment of the cam 54 immediately adjacent thestep 92on a center of curvature which is spaced from the center of curvature of the step itself and the periphery of the remaining portion of the cam 54.

The body portion 86 of the follower 84 is adapted to engage the cam track 90 for flexing the switch arms 22, 24 and 26 away from the cam 54 so as to thereby urge the contact 35 into engagement with the contact 28, the contact 28 into engagement with the contact 36, and the contact 30 into engagement with the contact 32. The floating cam follower 84 is receivable in the stepped cam track recess to effect in stages, as will be described in detail hereinafter, snap separation of the contacts 36, 28, 35, 32 and 30.

The mechanism of our present invention which is provided for opening momentarily the circuit between a pair of the afore-described switch arms during, and prior to completion of, a timed cycle of operationof the switch mechanism comprises switchactuating means, such as a lever 98, pivotally mounted intermediate of its ends at 100 to the cam 54. The right end of the lever 98, as viewed in Figure 2, is adapted to project beyond the periphery of the cam 54 alongside of the step 92. The other end of the lever 98 is formed with a finger portion 102 which projects through an aperture 104 formed in the cam 54 and is adapted to cooperate with the foot portion 49 of the slidable member 48. The lever 98 and the slidable member 48 constitute the means which is actuated by the cam follower 84 in one range of rotation of the cam 54 for separating the switch arms 22 and 38, and

disengaging the contacts 28 and 36.

The floating mounting of the cam follower 84 permits the latter, when moved to the cam track 90, to be pivoted so as to point in the direction that the cam 54 is to be power rotated. For example, if, to institute a timed cycle of operation, the cam 54 is manually rotated counterclockwise, from the position shown in Figure 3, the follower 84 initially pivots clockwise from the angle shown insolid lines to the angle shown in dotted lines, and ascends the right end of the step 96 of the cam track recess to the landing of the step 94, whereupon it snap pivots counter-clockwise and assumes the angle shown in solid lines in Figure 4. The snap action is obtained by offsetting the pivotal axis of the follower 84 from the axis of rotation of the cam 54.

During this manual counter-clockwise rotation of the cam 54, which is permitted because of slippage of a friction clutch employed in the timer motor and reduction gearing unit 76, the contact 35 is moved into engagement with the contact 28 and the contact 28 is moved into engagement with the contact 36; thus the three switch arms 22, 24 and 38 become electrically interconnected.

During further manual counter-clockwise rotation of the cam 54, the follower 84 pivots clockwise from the angle shown in solid lines in Figure 4 to the angle shown in dotted lines, and ascends the right end of the step 94 to the landing of the step 92, whereupon it snap pivots counter-clockwise and assumes the angle shown in solid lines in Figure 5. As soon as the follower 84 reaches the landing of the step 92 the button 34 moves the contact 30 into engagement with the contact 32 for completing an electrical circuit therebetween.

Still further manual counter-clockwise rotation of the cam 54 causes the follower 84 to move over the projecting edge of the lever 98 and to pivot clockwise from the angle shown in solid lines in Figure 5 to the angle shown in dotted lines, so as to facilitate its travel up the right incline of the step 92. As the cam follower 84 moves over the projecting end of the lever 98, the finger portion 102 of the latter engages the one side of the foot portion 49 of the slidable member 48 and pivots the latter about the upper pin member 44. Thus, during manual counterclockwise rotation of the cam 54, the switch actuating mechanism comprising the lever 98 and member 48 remains inoperative and does not interfere with the engagement of the switch contacts 35, 28 and 36.

The follower 84 next rides up the incline of the step 92, and, upon reaching the landing of the cam track 90, snap pivots counter-clockwise to the position shown in Figure 6. As the cam follower moves to the track 90, the finger portion 102 of the lever 98 swings below the foot portion 49 of the slidable member 48 and the latter is pivoted back to its normal position by means of the portion 52 of the switch arm 38. The follower 84 may be positioned at any point about the periphery of the cam 54, and upon completion of manual rotation of the cam 54, the motor assembly 76 will begin to rotate the cam clockwise.

The cam 54 may be rotated manually in a clockwise direction for instituting a timed cycle of operation. Upon manual rotation of the cam 54 in a clockwise direction from the position shown in Figures 2 and 3, the follower 84 initially tends to assume substantially the same angle as the left end of the step 96 of the cam track recess, thus facilitating travel of the follower up the incline to the cam track proper.

As the follower 84 rides up the incline, the switch arm 24 is flexed and the contact 35 is moved into engagement with the contact 28 for completing an electrical circuit therebetween. Continued manual rotation of the cam in a clockwise direction moves the follower 84 to the cam track at which point, as shown in Figure 7, the contact 28 is moved into engagement with the contact 36, and the contact 30 is moved into engagement with the contact 32, for completing electrical circuits respectively therebetween. After the cam follower 84 has been moved to the position shown in Figure 7, the motor assembly 76 takes over clockwise rotation of the cam 54.

The timed cycle is completed when the follower 84 enters the cam track recess. As the cam follower 84 approaches the cam track recess, the finger portion 102 of the lever 98 engages the lower part of the foot portion 49 of the slidable member 48, which serves as a reaction point, and the projecting end of the lever 98 is pivoted radially outwardly alongside of the step 92 of thecam trackrecess. The follower 84, upon leaving the cam track 90 and entering the step 92 of the cam track recess, first drops to the position shown in Figure 8 and engages the projecting end of the lever 98 for snap pivoting the latter clockwise and causing the finger portion 102 of the latter to move the foot portion 49 of the slidable member 48 and the switch arm 38 upwardly so as to effect a quick break of engagement between the contacts 28 and 36. Upon a slightly further rotation of the cam 54, the finger portion 102 of the lever 98 is moved out of engagement with the lower end of the foot portion 49 of the slidable member 48 for releasing the force applied thereto and permitting the switch arm 38 to snap back to the position shown in Figure 6 with the contacts 28 and 36 again in engagement. Through the functioning of the switch actuating means comprising the lever 9 and slidable member 43, the circuit between the switch arms 22 and 38 ismomentarily opened and then closed during, and prior to completion of, a timed cycle of operation of the switch mechanism. It is to be further noted that the contacts 28 and 36 are re-engaged without any radial movement being required on the part of the cam follower 84.

Still further rotation of the cam, 54 causes the cam follower 84 to drop to the step 94 and snap pivot from the angle shown in solid lines in Figure 8 to the angle shown in dotted lines in Figure 9. During this action, a quick break of engagement between the contacts 34) and 32 is effected.

In the final period of rotation of the cam 54, the follower 84 is pivoted from the angle shown in dotted lines in Figure 9 to the angle shown in solid lines, and then, upon entering the step 516, snap pivots from the angle shown in solid lines in Figure 9 to the angle shown in dotted lines in Figure 10. When the follower enters the step 96 of the cam track recess a quick break of engagement between the contacts 35, 28 and 36 is effected. If the timed cycle of operation is initiated again by manually rotating the cam 54 in a clockwise direction, the follower wili, to accommodate the setting, flip from the dotted line position shown in Figure to the solid line position.

It will be understood by those skilled in the art that the above described cycles of operation may be repeated as often as desired, and that the cycles of operation may be var ed by changing the diameter of the cam, by changing the arcuate length of the steps of the cam track recess, by increasing the number of recesses about the periphery of the cam, and/or by increasing the period of time in which the finger portion 102 of the lever s3 is maintained at the lower end of the foot portion 49 of the slidable member 48.

Now, while we have shown and described what we believe to be a preferred embodiment of our present inention, it will be understood by those skilled in the art.

that various rearrangements and modifications may be made therein without departing from the spirit and scope of our present invention.

We claim:

1. In a switch assembly, the combination of a revolvable main cam having a track with an abrupt radial recess, first and second switch arm means associated with said cam, a floating cam follower associated with said switch arm means and cngageable with said cam track for urging said second switch arm means into electrical communication with said first switch arm means, means establishing a pivotal axis for said cam follower which is offset from the axis of rotation of said cam for producing a snap action of said cam follower, a slidable member associated with said first switch arm means and being adapted to move the latter out of electrical communication with said second switch arm means, said slidable member being normally biased away from said first switch arm means and having a foot portion, a pivot pin around which said slidable member has pivotal movement, and supplemental cam means carried by said main cam for engaging the foot portion of said slidable member, said supplemental cam means being operative in one direction of rotation of said main cam to cause sliding movement of said slidable member, and being operative in the other direction of rotation of said main cam to cause pivoting movement of said slidable member around said pivot pin, one of said movements of said slidable member being operative to move said first switch arm means out of the electrical connection with said second switch arm means.

2. in a switch assembly, the combination of a revolvable main cam having a track with an abrupt radial recess, first and second switch arm means associated with said cam, a floating cam follower associated with said second switch arm means and engageable with said cam track for urging said second switch arm means into electrical communication with said first switch arm means, a slidable pivotable member associated with said first switch arm means and being adapted to move the latter out of electrical communication with said second switch arm means, and supplemental cam means rotating with said main cam and adapted in one direction of rotation of said main cam to engage said slidable pivotable member for causing sliding movement of the latter, whereby said first switch arm means is moved out of electrical communication with said second switch arm means, and adapted in the other direction of rotation of said main cam to cause pivoting movement of said slidable pivotable member.

3. In a. switch assembly, the combination of a revolvable cam having a track with an abrupt radial recess, a first switch arm mounted for movement between a circnit closing position and a circuit opening position, a fronting cam follower associated with said switch arm and engageab e with said cam track for urging said switch arm into one of said positions, said floating cam foliower being receivable in said cam track recess to effect a quick movement of said first switch arm into the other of said positions, a second switch arm mounted for movement between a circuit closing position and a circuit open- .in g position, a slidable pivotable member associated with said second switch arm and being adapted to move the latter from one of said positions to the other, and means associated with said revol /able cam operative in one direction of rotation of said revolvable cam for imparting sliding movement to said slidable pivotable member and operative in the opposite direction of rotation of said revolvable cam for imparting pivotal movement to said slidable pivotable member.

in a switch assembly, the combination of a revolvable cam, switch arm means mounted for movement into and out of engagement with a contact, a slidable member associated with said switch arm means and being adapted to move the latter out of engagement with said contact, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project beyond the periphery of the cam and the other end thereof being adapted to engage said slidable member, a cam follower associated with said cam, and said cam follower when moving into engagement with the said one end of said lever means serving to pivot the latter for causing sliding movement of said slidable member whereby said switch arm means is snapped out of engagement with said contact to effect a quick break of engagement therebetween.

5. In a switch assembly, the combination of a revolvable cam, switch arm means mounted for movement into and out of engagement with a contact, a slidable member ssociated with said switch arm means and being adapted to move the latter out of engagement with said contact, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project beyond the periphery of the cam and the other end thereof being adapted to engage said slidable member, a cam follower associated with said cam, said cam follower when moving into engagament with the said one end of said lever means during rotation of said cam serving to pivot the latter for causing sliding movement of said slidable member whereby said switch arm means is snapped out of engagement with said contact to effect a quick break of engagement therebetween, and said other end of said lever means upon further rotation of said cam moving out of engagement with said slidable member for releasing the force applied thereto and permitting said switch aim means to snap back into engagement with said contact.

6. In a switch assembly, the combination of a revolvable cam, a cam follower associated with said cam, switch arm means mounted for movement into and out of engagement with a contact, a slidable member associated with said switch arm means and being adapted to move the latter out of engagement with said contact, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project beyond the periphery of the cam, the other end of said lever means serving to engage said slidable member for pivoting the said one end of said lever means radially outwardly as the cam follower approaches the latter, said cam follower when moving into engagement with the said one end of said lever means during rotation of said cam serving to pivot the latter for causing sliding movement of said slidable member whereby said switch arm means is moved out of engagement with said contact, and

said other end of said lever means upon further rotation of said cam moving out of engagement with said slidable member for releasing the force applied thereto and permitting said switch arm means to snap back into engagement with said contact.

7. In a switch assembly, the combination of a revolvable cam having a track with an abrupt radial recess, a cam follower associated with said cam, switch arm means mounted for movement into and out of engagement with a contact, a slidable member associated with said switch arm means and being adapted to move the latter out of engagement with said contact, said slidable member being normally biased away from said switch arm means and having a foot portion, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project alongside of the cam track recess, the other end of said lever means during manual rotary setting of the switch assembly in one direction serving to engage the side of the foot of said slidable member for pivoting the slidable member to permit the said other end of said lever means to pass thereby without interfering with the relationship between said switch arm means and said contact, said slidable member being biased back to its normal position after passage of said other end of said lever means, and the said other end of said lever means during normal rotary operation of the switch assembly in the other direction servingto engage the bottom of the foot of said slidable member for pivoting the said one end of said lever means radially outwardly as said cam follower approaches the cam track recess, said cam follower when moving into said cam track recess during rotation of said cam being engageable with said one end of said lever means for pivoting the latter and causing sliding movement of said slidable member whereby said switch arm means is snapped out of engagement with said contact, and said other end of said lever means upon further rotation of said cam moving out of engagement with the foot of said slidable member for releasing the force applied thereto and permitting said switch arm means to snap back into engagement with said contact.

8. In a switch assembly, the combination of a revolvable cam having a track with an abrupt radial recess, first and second switch arm means associated with said cam, a floating cam follower associated with said second switch arm means and engageable with said cam track for urging said second switch arm means into electrical communication with said first switch arm means, a slidable member associated with said first switch arm means and being adapted to move the latter out of electrical communication with said second switch arm means, said slidable member being normally biased away from said switch arm means and having a foot portion, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project alongside of the cam track recess, the other end of said lever means during manual rotary setting of the switch assembly in one direction serving to engage the side of the foot of said slidable member for pivoting the slidable member to permit the said other end of said lever means to pass thereby without interfering with the relationship between said switch arm means, said slidable member being biased back to its normal position after passage of said other end of said lever means, and the said other end of said lever means during normal rotary operation of the switch assembly in the other direction serving to engage the bottom of the foot of said slidable member for pivoting the said one end of said lever means radially outwardly as said follower approaches the cam track recess, said cam follower when moving into said cam track recess during rotation of said cam being engageable with said one end of said lever means for pivoting the latter and causing sliding movement of said slidable member whereby said first switch arm means is moved out of electrical communication with said second switch arm means, and said other end of said lever means upon further rotation of said cam moving out of engagement with the foot of said slidable member for releasing the force applied thereto and permitting said first switch arm means to snap back into electrical communication with said second switch arm means.

9. In a switch assembly, the combination of a revolvable cam having a track with an abrupt multi-step radial recess, first and second switch arm means associated with said cam, a cam follower associated with said second switch arm means and engageable with said carn track for urging said second switch arm means into electrical communication with said first switch arm means, a slidable member associated with said first switch arm means and being adapted to move the latter out of electrical communication with said second switch arm means, said slidable member having a foot portion, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project alongside of one of the steps of the cam track recess, the other end of said lever means serving to engage the foot of said slidable member for pivoting the said one end of said lever means radially outwardly as said cam follower approaches the cam track recess, said cam follower when moving into said one step of said cam track recess during rotation of said cam being engageable with said one end of said lever means for pivoting the latter and causing sliding movement of said slidable member whereby said first switch arm means is moved out of electrical communication with said second switch arm means, said other end of said lever means upon further rotation of said cam moving out of engagement with the foot portion of said slidable member for releasing the force applied thereto and permitting said first switch arm means to snap back into electrical communication with said second switch arm means, and said cam follower upon still further rotation of said cam being receivable in another step of said cam track recess to effect a quick break away of said second switch arm means from engagement with said first switch arm means.

10. In a switch assembly, the combination of a revolvable cam having a track with an abrupt radial recess, first, second and third switch arm means associated with said cam, a cam follower associated with said third switch arm means and engageable with said cam track for urging said third switch arm means into engagement with said second switch arm means and said second switch arm means into engagement with said first switch arm means, a slidable member associated with said first switch arm means and being adapted to move the latter out of engagement with said second switch arm means while said second and third switch arm means remain in engagement, said slidable member having a foot portion, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project alongside of the cam track-recess, the other end of said lever means serving to engage the foot portion of said slidable member for pivoting the said one end of said lever means radially outwardly as said cam follower approaches the cam track recess, said cam follower when moving into said cam track recess during rotation of said cam being engageable with said one end of said lever means for pivoting the latter and causing sliding movement of said slidable member whereby said first switch arm means is moved out of engagement with said second switch arm means while said second and third switch arm means remain in engagement, said other end of said lever means upon further rotation of said cam moving out of engagement with the foot of said slidable member for releasing the force applied thereto and permitting said first switch arm means to snap back into engagement with said second switch arm means, and said cam follower upon still further rotation of said cam serving to effect a quick break away of said third switch arm means from engagement with said second switch arm means and second switch arm means from engagement with said first switch arm means.

11. In a switch assembly, the combination of a revolvable cam having a track with an abrupt multi-step radial recess, first, second and third switch arm means associated with said cam, a cam follower associated with said third switch arm means and engageable with said cam track for urging said third switch arm means into engagement with said second switch arm means and said second switch arm means into engagement with said first switch arm means, a slidable member associated with said first switch arm means and being adapted to move the latter out of engagement with said second switch arm means while said second and third switch arm means remain in engagement, said slidable member having a foot portion, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project alongside of one of the steps of the cam track recess, the other end of said lever means serving to engage the foot of said slidable member for pivoting the said one end of said lever means radially outwardly as said follower approaches the cam track recess, said cam follower when moving into said one step of said cam track recess during rotation of said cam being engageable with said one end of said lever means for pivoting the latter and causing sliding movement of said slidable member whereby said first switch arm means is moved out of engagement with said second switch arm means while said second and third switch arm means remain in engagement, said other end of said lever means upon further rotation of said cam moving out of engagement with the foot portion of said slidable member for releasing the force applied thereto and permitting said first switch arm means to snap back into engagement with said second switch arm means, and said cam follower upon still further rotation of said cam being receivable in another step of said cam track recess to effect a quick break away of said second switch arm means from engagement with said first switch arm means and said third switch arm means from engagement with said second switch arm means.

12. In a switch assembly, the combination of a revolvable cam having a track with an abrupt multi-step radial recess, first, second and third switch arm means associated with said cam, fourth switch arm means mounted for movement into and out of engagement with a contact, a cam follower associated with said third switch arm means and engageable with said cam track for urging said third switch arm means into engagement with both said second switch arm means and said fourth switch arm means whereby the latter is moved into engagement with said contact, said cam follower when engaging said cam track also serving to urge said second switch arm means into engagement with said first switch arm means, a slidable member associated with said first switch arm means and being adapted to move the latter out of engagement with said second switch arm means while said second and third switch arm means and said fourth switch arm means and contact remain respectively in engagement, said slidable member having a foot portion, lever means pivotally mounted intermediate of its ends to said cam with the one end thereof being adapted to project alongside of one of the steps of the cam track recess, the other end of said lever means serving to engage the foot of said slidable member for pivoting the said one end of said lever means radially outwardly as said follower approaches the cam track recess, said cam follower when moving into said one step of said cam track recess during rotation of said cam being engageable with said one end of said lever means for pivoting the latter and causing sliding movement of said slidable member whereby said first switch arm means is moved out of engagement with said second switch arm means while said second and third switch arm means and said fourth switch arm means and contact remain respectively in engagement, said other end of said lever means upon further rotation of said cam moving out of engagement with the foot of said slidable member for releasing the force applied to and permitting said first switch arm means to snap back into engagement with said second switch arm means, said cam follower upon further rotation of said cam being receivable in a second step of said cam track recess to effect a quick break away of said fourth switch arm means from engagement with said contact, and said cam follower upon still further rotation of said cam being receivable in another step of said cam track recess to eifect a quick break away of said second switch arm means from engagement with said first switch arm means and said third switch arm means from engagement with said second switch arm means.

References Cited in the file of this patent UNITED STATES PATENTS 1,129,446 Brinton Feb. 23, 1915 1,257,694 Gadke Feb. 26, 1918 1,550,312 Fouke Aug. 18, 1925 1,634,083 Rutenber June 28, 1927 1,909,138 Vollmer May 16, 1933 2,020,974 Truesdell Nov. 12, 1935 2,025,859 Hartman Dec. 31, 1935 2,266,248 Osterheld Dec. 16, 1941 2,728,822 Stolle et al. Dec. 27, 1955 2,737,548 Mead Mar. 6, 1956 

